From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0035729D0E; Sat, 8 Feb 2025 00:28:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738974526; cv=none; b=JRPd4xyU5k3K0jyTo8nk3bNj28o9wd7pf9kFcdAVSMwisE7atrbParwQmDScVhkVzWXKzUKCEsduI+TwL/aY4/DvF1BaZvc/J/JQ3ysAg/ibpTO/zGU7O4dOF8Pf/hArJcSSpzYMhP3isPO64K5XCT1vJK8Q4Ex4yL/7ZGZ/Dq0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738974526; c=relaxed/simple; bh=u6eQSkM7Cfs+opcao0mVLmHYFdxwwlZIySepbPrVVzE=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Q0nkCXGgBxWF2uE1pBxfxrp6n+bK+P1gxtWP7UDZepoe++ir05epx8MmXUZUR0UO5zze+GIB2DJ78mGmY95ZiCckGWjK9IjtQb+HLZp4pk9HBhkOs3om9TLO3p2PCnukraOw/KEXkMygunbhI4yEUdII13fjMITvFFL2sfFOz2k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IOpWvW0+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IOpWvW0+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD5F2C4CEE4; Sat, 8 Feb 2025 00:28:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738974525; bh=u6eQSkM7Cfs+opcao0mVLmHYFdxwwlZIySepbPrVVzE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IOpWvW0+YdUJ3ap6jQntf+5RAp4ed5ewCfgDB6op9LLzT6FVKaWHlWOc4ZMgg/HRC hbhP4gOwkSaiJslF3QGrcpqNyGCHtI6Tss8B8d4nwyD5t+3/7MLd16KxxlQS4uRY3f pBckzRjCmZIjLYlVFYKBOanTd5bhEoqcPV/CaSGsRT3ICWBwlTcPtpVJa1HHoCawmF VpTlThGRN4aJOSvIDlnckWMEtt23ZETAgvBt4UUZyGtvP8CHPyknolOXN6pjPYJyMi SAP0dltglldLXNba1Lyvj4n5MsHEwzm8H+W62oZ5HV3CgsxFKea8Xb9roqOwdwnaLc iXaFxcyoyyF7A== Date: Fri, 7 Feb 2025 16:28:44 -0800 From: Jakub Kicinski To: Uday Shankar Cc: Breno Leitao , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Srinivas Kandagatla , =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= , Simon Horman , Andrew Morton , Johannes Berg , Jonathan Corbet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v3 2/2] netconsole: allow selection of egress interface via MAC address Message-ID: <20250207162844.43b20256@kernel.org> In-Reply-To: <20250205-netconsole-v3-2-132a31f17199@purestorage.com> References: <20250205-netconsole-v3-0-132a31f17199@purestorage.com> <20250205-netconsole-v3-2-132a31f17199@purestorage.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 05 Feb 2025 22:21:31 -0700 Uday Shankar wrote: > Currently, netconsole has two methods of configuration - module > parameter and configfs. The former interface allows for netconsole > activation earlier during boot (by specifying the module parameter on > the kernel command line), so it is preferred for debugging issues which > arise before userspace is up/the configfs interface can be used. The > module parameter syntax requires specifying the egress interface name. > This requirement makes it hard to use for a couple reasons: > - The egress interface name can be hard or impossible to predict. For > example, installing a new network card in a system can change the > interface names assigned by the kernel. > - When constructing the module parameter, one may have trouble > determining the original (kernel-assigned) name of the interface > (which is the name that should be given to netconsole) if some stable > interface naming scheme is in effect. A human can usually look at > kernel logs to determine the original name, but this is very painful > if automation is constructing the parameter. > > For these reasons, allow selection of the egress interface via MAC > address when configuring netconsole using the module parameter. Update > the netconsole documentation with an example of the new syntax. > Selection of egress interface by MAC address via configfs is far less > interesting (since when this interface can be used, one should be able > to easily convert between MAC address and interface name), so it is left > unimplemented. Sounds like dev_getbyhwaddr_rcu() will warn here. Either wrap it in RCU temporarily or combine the series with Breno's patch to add a new helper? -- pw-bot: cr